SANTA CLARA, Calif.--(BUSINESS WIRE)--XenoPort, Inc. announced today that the U.S. Food and Drug Administration (FDA) will not be taking an action today on the Horizant (gabapentin enacarbil) new drug application (NDA) for moderate-to-severe primary Restless Legs Syndrome (RLS), due to the fact that the federal government has been closed for the past two days. The FDA has indicated that the new Prescription Drug User Fee Act (PDUFA) goal date is Thursday, February 11, 2010, assuming that there are no further federal government closings this week. The FDA indicated that if there are additional federal government closings this week, the goal date for this NDA will likely be extended further.

This NDA was filed by GlaxoSmithKline (GSK), XenoPort’s partner in the United States and several other countries outside of Asia. Horizant is also known as XP13512.

About XenoPort

XenoPort, Inc. is a biopharmaceutical company focused on developing a portfolio of internally discovered product candidates that utilize the body’s natural nutrient transport mechanisms to improve the therapeutic benefits of existing drugs. The FDA is currently reviewing GSK’s NDA for Horizant/XP13512 as a potential treatment for RLS. XenoPort is developing its lead product candidate, XP13512, in collaboration with Astellas Pharma Inc. and GSK. XenoPort’s product candidates are being studied for the potential treatment of gastroesophageal reflux disease, migraine headaches, neuropathic pain, spasticity and Parkinson’s disease.

To learn more about XenoPort, please visit the web site at www.XenoPort.com.

Forward-Looking Statements

This press release contains “forward-looking” statements, including, without limitation, all statements related to the anticipated Horizant NDA PDUFA date and the timing thereof. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Words such as “will” and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based upon XenoPort's current expectations. Forward-looking statements involve risks and uncertainties. XenoPort's actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, risks related to the uncertainty of the FDA approval process and other regulatory requirements, and the timing thereof. These and other risk factors are discussed under the heading “Risk Factors” in XenoPort’s Quarterly Report on Form 10Q filed with the Securities and Exchange Commission on November 4, 2009. XenoPort expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in the company's expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based.

Horizant is a trademark of GSK. XenoPort is a registered trademark of XenoPort, Inc.